Hollow hydraulic jack



W. S. PINE I Jan. 22, 1946.

HoLLow HYDRAULIC JACK Filed sept. 22 1942 Patented Jan.f22, 1946 UNITEDSTATES PATENT OFFICE v HOLLOW HYDRAULIC JACK William S.`Pine, Southgate,Calif.

Application September 22, 1942, Serial No; 459,256

I (Cl. 30g-.34)

2 Claims.

My invention relates to a hydraulic jack and particularly to a jack ofthis class for drawing two or more members relative to each other.r

An important object oi' this invention is 'to provide a simple andeillcient hydraulic jack which will serve as an ordinary jack forraising objects above and also upwardly from below the Jack; and whichwill also serve for drawing two or more members together, or forwithdrawing A further object of this invention is to provide I simpleand efcient means for transferring the liquid from the reservoir'intothe compresison chamber. l

An important object of this invention, also, is

to provide a novel and efilcient method of constructing and finishing.the adjacent surfaces of two concentric cylinders for a jack of thisclass. and in which there is provided a narrow annular cylindricalspaceA of 'considerable depth therebetween.

' A further important object of this invention is to provide novel,simple and economical means A of variously sealing the'liquidof thehydraulic jack against escape.y and toV provide especially tight jointsbetween mutually reciprocating cylindricalparts to withstand unusuallyhigh fluid pressure, and provide novel and effective means-v of securingthe sealing means in place.

- With these and other objects in view, as will appear hereinafter, Ihavedevised` a hydraulic jack of this class having certain novelfeatures of construction, combination and arrangement Fig. 3 is asectional elevation thereof taken through-3 3 of Fig. l;

Fig. 4 is an enlarged'fragmentary sectional view showing the sealingmeans between the plunger and the cap of the cylinder;

Fig. 5 is an other enlarged fragmentary slightly exploded sectionalvview showing particularly the means for forcing the sealing leatheragainst thewall of a relatively movable member; and

Fig. 6 is an end view of the head of the pump plunger taken through 6 3of Fig. 3.

The enclosing housing of my hydraulic 'jack consists of an outercylinder I, an inner concentric cylinder 2, and a thick head 3connecting the lower ends of said cylinders, which head v forms the baseof the jack. The space between the cylinders I and 2 provides arelatively narrow annular compartment or annular cylindricalv space Ainto which extends the lower portion of the moving or extensible memberof my jack, which is the plunger. This moving member consists oi anannular piston 4 which has at its radially inner portion an upwardlyextending tubular piston rod or shank 5. The upper end of the tubularpiston rod portion has an axial opening 5* which is smaller in diameterthan the main portion of the piston rod, forming a shoulder 5b which isadapted to engage the upper end .of t e inner cylinder 2 for limitingthe lower posi ion of the piston. The diameter of the opening I5* issubstantially the same as the inside The upper.

diaineter of the inner cylinder 2.` en/d of the space between the outercylinder I and the tubular piston rod is enclosed by a cap 6;' which isscrewed over the upper end of the outer cylinder. The main enclosuremember of my jack, con- `sisting of the cylinders I and 2 and the base3, is f made by forming the cylinder I and the base 3 as one member,machining the inner cylindrical wall of the cylinder I, machining theexterior surface of a tubular member to form the cylinder 2,

of parts and portions, as will be hereinafter described in detail, andparticularly set forth in the appended claims, reference being had tothe ac.

companying-.drawlng and to the characters ofy reference thereon, whichform a part of this application, in which:

Fig. l is a top view of my hydraulic jack in" a I preferred form,portions thereof being broken away to facilitate the illustration;

Fig. 2 is a fragmentary side elevation thereof, also showing portionsbroken away and in section, the sectional portion being taken through2--2 o! Fig. l;

and then welding or otherwise securing the lower end of the cylinder 2into a corresponding hole in the base 3, as indicated by B in Fig. 3.

The piston rod 5 and the piston 4 fit loosely in the space A, and thetubular piston rod extends loosely through the axial portion of the cap6. There'are, however, provided means in connection with the piston andcylinders, means for A sealingthe respective joints between saidmembers.

At the lower end or face of the piston is secured a sealing leather 1which is of inverted U-shaped cross-section, the outer leg or flange 1aengaging 2 I f aaeauo the inner wall of the outer cylinder while theinner leg or flange 1b engages the outer surface of the inner cylinder.This sealing leather is secured in place by an annular retaining ring orplate 8 located within the hollow portion ofthe sealing leather, theannular retaining ring being secured to the lower face of the piston byscrews 9.

In a cupped sealing leather of this type, the outer flange Ia normallyengages tightly the inner surface of the outer cylinder. I haveprovided, however, a flexible and elastic vannular member I which isseated lwithin an annular groove 8a, this groove being provided in thebore of the retaining member. The central opening of the'flexible memberI0 is bevelled at the upper portion and this bevelled portion engagesthe correspondingly bevelled lower edge of the cup or sealing leather 1.As the retaining member 8 is clamped in position, the elastic member I0forces the inner flange of the cup leather against the outer face of theinner cylinder 2v designated A2, is the reservoir for the liquidformotivating the jack. In the cap 6 is provided a sealing ring Il forpreventing escape ofthe liquid from the reservoir A2, particularly when'cross-section, the outer leg II being positioned at the bottom of agroove Ba, in the wall of the; bore of the cap, and the outer side ofthe other leg I Ib being positioned in engagement with the outercylindrical surface `of the-piston rod 5. The inner leg I Ib terminatesina feather edge and is resiliently forcedi'a'gainst the piston rod, thedotted lines. in Fig'. iindlcati'ngthe normal shape of the innerleg.' of.the sealing ring before engaging thepiston rod. 1

The fluid of my jack is transferred from the reservoir A2 into thecompression chamber A1 by a` pump mechanism placed preferably at theside of the outer cylinder I. This pumip mechanism consists essentiallyof a cylinder 2| and a plunger 22. The cylinder is shown as screwed atits lower end into a fitting 23 and the fitting 23 isV secured at itslower end in a threaded recess 24a of va base 24 secured' to and formingsubstantially a lateral extension of the base 3 of the jack. At theupper end of and around the plunger 22 is provided a stuffing box 25.The plunger is provided with an enlarged bifurcated head 22a which is24b on the base 24.

At the exterior of the outer cylinder is provided a conduit 28 which maybe made as a. part of the outer cylinder I. This conduit is connected atupper portion of the reservoir.

of the conduit 28 is connected by means'of a 70 transverse port 24c withtan;` annular channel at the lower and peripheral portionofthe threadedplug of the fittingv 23, the channel vbeing formed by a groove .2'3a attheglower end of the fitting. The fitting' 23 is providedwith twolongitudinal 59 .engaging'the cap Banditliespiston 4.-

passages 2lb and'swgztheiormer'being positionedk at the side of thefittingandex'ndingffrom said annular channel to the upper end oftlrez-ttl'ns or to thev threaded recess receiving the lower end 5 of thecylinder 2i the other .passage 23 extends to pass into the cylinder 2land the latter preventing a return of fiuid into the cylinder. The lowerend of the passage 23c communicateswith a transverse passage 3 whichcommunicates with the lower end of the annular compression chamber A1through a port in the base 3. In this manner fluid is forceablytransferred from the reservoir to the compression chamber.

The interior of the outer cylinder I is also connected with the conduit28 by means of a small by-pass orifice 28", this orifice beingpositioned below thev port 28EL so as to prevent the lower end of thesealing leather 'I to be forced outwardly beyond the orice 28.

At the juncture ofthe conduit 28 and the horizontal passage 24 isprovided a thimble screen 3l which may be inserted through 'an openingnormally closed by a plug 32. At the lower end of vthe intake passage23b is also provided a screen 30 In order to relieve the pressure withinthe compression chamber A1 and allow the liquid again to be transferredto the reservoir A, I have provided a release valve whichconsists of aball 4I and arelease jscrew- 42. Theball 4I, when it isdesiredztd'prevent the lreturn,offluid, is seated the jack is used inany other than an upright` Y position. This ring is also of invertedU-shaped viiends; inagibilit# isgrconnected with theannularlpa'ssage/ppwided 'by the channel 23a by means of an angularport24f, as shown in Fig. 1. Thus, the liquidfin the `compression chamber ofthe jack-is returned tothe vvreservoir through the i c' r1; 'zs\-.-

- Tofacilitate `the return-,ofi'thei-pifston to its =lowered position, Ihave `provided -a 'compression coil spring ll within ,the reservoiry A,its ends ,usages-3, 24d,`24, 241, 23, 24e, yconduit 28 and vjackyis.constructed fora-drawing two memv` bers ltogfetlier, lor-forzraisingobjects from below i j For this reason, theinslde diameter rcylinder isrelatively large, and the u al .o p ning 5, atthe upper end of thepiston rod, iscorrespondingly large, To raise an ob- ',ject from belowthejack, a rod 6i may be placed 'through .the axial' portion of the jackand the 'upper endmay be supported by a supporting disc a ,162, orltheilike, on the -upper end of the piston rod, pivotally connected tothe intermediate portion of an operating lever 26. The end of theoperating lever is pivotally connected bya link 21 to a boss asshown inFig. 3.

'I'hough I have shown and described a particular construction,combination and arrangement of parts and portions, I do not wish to beylimited to the same, but desire to include in the scope of my inventionthe construction, combination, and arrangement substantially as setforth in the ap pended claims'.l

, v,I claim:

1. A- machine of the class described, a. cylinder, a piston reciprocallymounted therein, a sealing leather member having a flange positionedagainst the face of the piston head and a second fiange engaging thecylinder wall, the edge oi the second flange being bevelled towards thefirst flange, an annular plate securing the rst ange to the piston, saidplate' being provided in its side wall with an annular groove, and aflexible annular member mounted with a portion in the groove andextending with its other beyond the plate, the outer portionof theflexible member' being bevelled and"engaging the bevelled outer edge ofthe second flange for forcing said flange against the wall of thecylinder, said flexible annular member being positioned radiallyoutwardly from the second `flange for resiliently contracting thediameter of the second flange around the wall of the cylinder. Y

2. A machine of the classdescribed, a cylinder,

a piston reciprocally mounted therein, a sealing 15 leather memberhaving a flange positioned against the face of the piston head and asecond flange engaging the cylinder wall, the edge-of the second flangebeing bevelled towards the rst flange, an annular plate securing thefirst flange to the piston, said plate being provided in its side wallwith an annular groove, and an elastic annular member mounted with aportion in the groove and extending with its other portion beyond theplate, the outer portion of the elastic member being bevelled andengaging the bevelled outer edge of the second flange for forcing saidflange against the wall of the cylinder, said elastic annular memberbeing positioned radially outwardly from thesecondflange for resilientlycontract ing the diameter of the sec'ond flange around the wall of thecylinder.

